Such an arrangement comprises a flap that forms an integral part of the instrument panel body while having its generally rectangular outline delimited by a precut made in the underside face of the instrument panel body so that this flap is not visible to an occupant of the vehicle.
An inflatable airbag module is fixed to the underside face of the instrument panel body, in the region of the flap, so that when airbag inflation is triggered, this airbag applies pressure to the underside face of the flap to cause this flap to open by breaking along the precut line. The opening of the flap then allows the airbag to deploy into the passenger compartment of the vehicle in order to protect the corresponding occupant.
Such a flap typically has a rectangular outline and is articulated with respect to the rest of the body of the instrument panel at the transverse edge of its outline that is closest to the windshield of the vehicle.
In order to prevent the flap from striking the windshield as it opens, it is known practice to provide one or more tethers which are fixed to the flap and to the rest of the instrument panel body.
This or these tether or tethers protrude beyond the opposite edges of the outline of the flap which are oriented in the direction of forward travel of the vehicle, and are secured to a fixed part of the assembly while at the same time being relatively slack between this fixed part and the flap. When the airbag inflates, the opening of the flap is limited by the length of the tether or tethers which then become taut when the flap reaches a certain degree of opening.
In one solution known from Patent Document EP0872389, a single tether is provided, in the form of a loop the two strands of which extend transversely over the entire width of the flap, and the ends of which are secured to fixed attachments situated at the level of the airbag module. This looplike tether is secured to the flap by being interposed between the underside face of the flap body and a flap reinforcing plate which is fixed to this underside.
In practice, the speed with which the airbag inflates generates significant mechanical stresses in the flap when the tethers suddenly become taut under the effect of this inflation in order to limit the opening of the flap.
These stresses may cause the reinforcing plate and/or the flap body to tear or even to be destroyed, thereby generating a risk of the broken parts of this plate being thrown out toward the occupant or occupants of the vehicle.